Intermittent drive mechanism



Nov. 26, 1963 INTERMITTENT DRIVE MECHANISM Filed April 12, 1961 2 Sheets-Sheet 1 @Y EN BY/ /Al Nov. 26, 1963 J. H. DRILLlcK 3,111,854

INTERMITTENT DRIVE MECHANISM Filed April 12, 1961 2 sheets-sheet 2 INVENTOR. M605 Maf/4me E15; -E B United States Patent O 3,111,854 ENTERMITTENT DRIVE MECHANISM Jacob H. Drillick, Granada Hiils, Calif., assigner, by

mesne assignments, to Clary Sales & Supply Corporation, San Gabriel, Calif., a corporation of California Filed Apr. 12, 1961, Ser. No. 192,451 14 Claims. (Cl. 74-126) This invention relates to high speed intermittent drive mechanisms and has particular reference to intermittent rotary drive mechanisms such as are employed to intermittently feed record media through data recording punches or readers.

Heretofore, intermittent mechanisms of the above type have generally comprised pawl and ratchet devices which `are generally satisfactory under relatively slow speed operation. However, as higher speeds 'are encountered, the ratchet tends to overthrow due to the rapid acceleration and deceleration forces involved. Allthough attempts have been made to overcome this tendency by the use of pawl jamming devices, etc., such devices are inherently noisy and contirbute to Wear and excessive strain on the parts.

It therefore becomes a principal object of the present invention to provide a relatively high speed intermittent drive mechanism in which the danger of overthrow of the intermittently driven element is greatly reduced.

Another object is to provide a high speed intermittent drive mechanism which is relatively quiet and free from wear.

Another object is to provide a high speed intermittent drive device which may be readily reversed.

The manner in which the above and other objects of the invention are accomplished will be readily understood on reference to the following specification when read in conjunction with the accompanying drawings, wherein:

FlG. 1 is an enlarged plan view, partly in section, of a tape feed mechanism embodying a preferred form of the present invention.

FIG. 2 is a transverse section view taken substantially along the line 2--2 of FIG. 1 illustrating the direction control mechanism 4in a forward condition.

FiG. 3 is a transverse section view similar to FIG. 2 but illustrating the direction control mechanism in a reverse direction.

FIG. 4 is an enlarged fragmentary section view of a portion of the feed sprocket illustrating the attachment of 'a sprocket tooth.

FiG. 5 is a transverse section view taken substantially along the line 5-5 of FlG. 1 illustrating one form of oscillating actuator ffor operating the tape feed mechanism.

FIG. 6 is a transverse section view taken substantially along the line 6-6 of FIG. 1 illustrating the centralizing mechanism for the feed sprocket.

FIGS. 7, 8 and 9 are diagrammatic views illustrating the relative positions of the tape sprocket drive parts at different points in a forward tape feeding cycle.

FiGS. 10 and 11 are diagrammatic views, similar to FGS. 7 and 8, but illustrating the relative positions of parts -at corresponding points in a reverse tape feed cycle.

The mechanism of the present invention is intended to be incorporated in a tape punch of the type disclosed and claimed in my co-pending application, Serial No. 102,526, dated April 12, 1961, for Perforating Apparatus. Accordingly, reference is hereby made to said co-pending application for a disclosure of mechanisms, such as tape punching and guiding means, mechanism driving means, etc., not specifically disclosed herein. It should be u-nderstood, however, that the present invention is equally applicable to other types of tape or strip handling mechanisms such as punched tape readers and tape printers.

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The tape feeding mechanism, in general, is mounted on a base 11 having an upwardly extending U-shaped wall section 12. The latter forms a compartment enclosed :by a front plate 13 which is suitably secured to the wall section 12.

A sprocket support shaft 14 is secure-d `at one end in a bracket 15- extending upwardly from the base 11 and at its opposite end in a bushing l16 carried by the front plate 13. Rotatab-ly mounted on the shaft 14 are a sprocket 17, a pawl `Li and a wedging or camming element 2G, each rotatable relative to the other. The sprocket 17 and element 26 are maintained a fixed distance ,apart in an axial direction by the pawl 18 may 4move axially a limited amount `as will appear later. For this purpose, the plate 13 `forms a base against which the element 2()l bears.

The sprocket 17 contains la row of tape feed teeth 21 which engage perforations 22 regularly spaced along the length of :a tape 23 to be fed. The teeth 21 are generally cylindrical, as seen in FIG. 4, and are fitted in radially extending holes formed in the sprocket 17, which holes communicate with :an annular groove 24 also formed in the sprocket. Each of the teeth has a groove 25 formed therearound enabling the sprocket teeth to be retained in place by `a suit-able cement 26 which iills the groove 24 and surrounds the teeth 21.

The sprocket 17 is angularly adv-anced one increment at a time in either direction an amount equal to the angular distance between the axes of adjacent sprocket teeth and is yieldably held in each advanced position by a detent device shown in FIG. 6. The latter comprises arms 271and 28 pivoted at 30 and 31, respectively, on a bar 32. The `arms are urged toward each other by a spring -3'3 tensioned therebetween and each carries a roller 34 at its lfree end which engages one off a series of regularly spaced notches 29 formed around the periphery of the sprocket. The bar 432 is pivotally supported at 35 and -is angularly adjustable by screws 36 whereby to angularly adjust the detended position of the sprocket.

The pawl 18 is oscillated about the shaft 14 by an amount substantially equal to the angular spacing between the teeth 21 during each cycle of the mechanism. For this purpose, an actuator generally indicated at 37 is provided, the latter being similar to that shown 4in detail in lthe aforesaid ico-pending application. The actuator is driven by two continuously rotating rolls 38 and 40 which rotate as indicated by the arrows A. Such rollers are arranged to frictionally drive an eccentric roller fit1 pivotally mounted at 42 on an actuating lever d3. The lever is pivotally supported at 441 and is pivotally connected at 45 to a threaded nut 4o. A rod 47 forming a Link is threaded in the nut 146 and also in a second nut 4S which is pivotally connected at 50 to the pawl 18. The threaded connections at opposite ends of the rod 47 are preferably arranged yat diffe-rent helical angles so that the distance between the pivotal connections t5 and 50 may be adjusted by appropriately turning the rod 47. rEhe pivotal connections 45, 46, 4S and 511 also permit a slight axial movement of the pawl 1S.

The roller i1 has a peripheral groove 51 therein which is frictionally engageable by mating portions of the rolls 3S and riti. However, the roller is normally prevented from being frictionally rotated by a brake piece 52 pivoted at 53` on the lever 43. In its normal arrested position, as illustrated, the roller 41 is located with the center of its periphery directly below the center of its rotatable support. The brake piece is also pivoted at 54 to a link 55 which, in turn, is pivotally connected to an armature 56 lfulcrumed at 57 and cooperable lwith an electromagnet 5S.

When the electromagnet is energized (usually as an incident to a normal tape processing operation), the armature 56 is drawn clockwise against the action of a suitable spring (not shown) to rock the brake piece 52 counter-clockwise and thus release the eccentric roller 4l. to rotation by the roll 40.

No'w, as the roller 4l is rotated, its pivotal support 42 will tirst be moved downwardly, thereby rocking the lever 43, and consequently pawl l, clockwise. Subsequently, the rolls 3S and 4d will `be effective to concurrently drive the roller back to its original position as shown to return the lever 43 and pawl, and at the completion of such cycle, the roller will engage the brake piece 52 which has, in the meantime, been returned to its initial illustrated position.

lt will be noted that the pawl 1S and sprocket 17 have a series of regularly spaced radially extending V-shaped teeth `or projections 65 and 66, respectively, on their adjacent end faces whereby to transmit rotary movement from the pawl to the sprocket. Also, the adjacent end faces of the camming element 20 and pawl are provided with a second series of regularly spaced radially extending V-shaped teeth or projections 67 and 68, respectively.

The sides of each of the teeth 67 and 65 preferably extend at the same Iangle a (FIG. 7) to the coincident axis of the elements i118 and l2t), which angle is of the order of 65 degrees. Likewise, the sides of each of the teeth 65 and 66 extend at the same angle b, which angle is the same as angle a. Also, the sides of the various teeth extend equi-angularly about such axis. In other words, the sides of the various `above teeth extend parallel to each other. However, the teeth 67, 68 are preferably twice the size of the teeth 65, 66.

It should be noted that the pawl 1S is permitted to moxe axially an amount suicient to permit the teeth 65 to pass by the teeth 66 in an angular direction about the shaft 14. However, this freedom of axial movement is insufficient to permit the teeth 68 to pass by the teeth 67.

Normally, the pawl 18 is held in its right-hand position shown in FIGS. l, 7 and lOl to maintain the teeth 65 and y66 in full engagement by the camming element 20 and by a compression spring 70 which surrounds the sprocket shaft ld.- and extends between the pawl l and the bushing 16.

Describing now the tape feed direction reversing mechanism, the camming element 20l carries a radially extending pin 71 which is normally engaged by the lower leg "l2 of a wire spring, the latter being wrapped around a pivot stud 73 and terminating in an upper leg 74. The spring legs 72 and 74 extend adjacent ears 75 and 76, respectively, of a direction control lever 77 pivoted on the stud 73. The latter is provided with a projection 78 engageable with a manually operable plunger `801. The ears 75 and 76 are located above and below the pin 7l and therefore serve to limit rotational movement of the camming element Ztl.

The lever "i7 is pivotally connected to the upper end of a slide Si which engages at its lower end the movable blade of a normally open contact switch 82. Switch 82 is preferably connected in circuit with the electromagnet 58 of FIG. 5.

A compression spring 3 is interposed between a switch support element 84 and a disc S5 fixed on the slide dl to normally hold the lever 77 in its clockwise rocked position shown in FlG. 2. The lever 77 carries a pin 86 which, when the lever 77 is in its position shown in FIG. 2, urges the camming element counterclockwise or in the direction of the arrow C (FIG. 7).

Upon depression of the plunger 801, as shown in FlG. 3, the lever 77 is rocked counte'rclockwise, causing its pin 36 to likewise rock the wire spring and thus cause its upper leg 74 to urge the camming element Z0 clockwise in FIG. 3 or in the direction of the arrow B in FIG. 101, causing it to assume its position shown in FIG. 10i relative to the pawl l. During the inal movement of the plunger 80, the slide 8l will close the switch 32 to energize the electromagnet 5d and thus initiate a tape feeding operation.

Describing now the operation of the tape feed rnecha-' nism in the forward direction, `it will be recalled that' the actuator o-f FIG. 5 is effective during a cycle of opera-j tion to first advance the pawl 18` clockwise from an initial position `and to thereafter return the same. Accordingly# since the side faces of the teeth 66 and 67 are parallel,-

the pawl will advance in the direction of arrow F against the action of spring 70, causing the sides of the teeth 65 and 68, which are non-driving during forward operations, to slide -along the adjoining teeth 66 and 67 of the pawl and camming element without advancing either of these latter items. This advancement will continue until the tips of the teeth 65 pass the tips of the teeth 66 as shown in FIG. 8. Thereafter, the spring leg 72 will become effective to move the camming element Eil further in the direction of arrow C to assist the spring '7G in moving the pawl to the right so as to again fully engage the teeth 65' and 66 as shown in FIG. 9.

It will be noted that during the above action, the teeth 67 and 63 do not at any time become fully engaged or bottomed.

Now, during return of the pawl 1S by the actuator, it will be seen that the teeth 65 and 66 are held fully engaged due to the spring biasing of the camming element 2.0 in the direction of the arrow C. Accordingly, the pawl will transmit an advancing movement to the sprocket against the action of its centralizer until the sprocket is centralized lin its new position at the completion of the cycle.

Describing now the operation of the tape feeding means in lthe reverse direction, it will be recalled that depression of the plunger Sti, as shown in FlG. 3, will yieldably move the camming element 20 clockwise or in the direction of the arrow B in FIG. l0. This will cause the opposite sides of the teeth 67 to engage the opposite sides of the teeth 68.

Therefore',l `as the pawl l5 moves through the rst portion of its stroke, the camming element 26' will maintain the teeth of the pawl in full engagement with the teeth 66 of the sprocket to drive the sprocket in the reverse direction. Later, `as the pawl' returns, it will move in the direction of the arrow G as the non-driving sides of teeth 65 and 68 slide along the parallel faces of the teeth 66 and 67, respectively, until the tips `of the teeth 65 pass the tips of teeth 66 as shown in FIG. 1l. Now, the upper spring. leg 74 becomes effective to urge the camming element Z0 further in the direction of the arrow B to cam the pawl toward full engagement with the teeth of the sprocket.

It will be noted that since the pawl contains a large number of both driving and camming teeth, any wear will be distributed among such teeth to reduce any overall wear.

Although the invention has been described in detail and certain specific terms and languages have been used, it is to be understood that the present disclosure is illustract-ive rather than restrictive and that changes and modications may be made without departing from the spirit or scope of the invention as set forth in the claims appended hereto.

Having thus described the invention, what is desired to secure by United States Letters Patent is:

l. An intermittent rotary drive mechanism comprising the combination of `a rotatable driven element, an oscillatable pawl element, one of said elements having a plurality of teeth therearound, the other of said elements having at least one tooth engageable with said rst mentioned teeth, a wedging element movable relative to said pawl element, said wedging element being engageable with said pawl element and adapted to :maintain said pawl element in driving engagement with said driven element by wedging action during movement of said pawl element in one direction, and means for yieldably urging said wedging element in the opposite direction, said wedging element permitting said pawl element to withdraw from driving engagement with said driven element during movement `of said pawl element in said opposite direction.

2. An intermittent rotary drive mechanism comprising the combination or" a rotatable driven element, an oscillatable pawl element, one of said elements having a plurality of teeth therearound, the other of said elements having at least one tooth engageable with said first mentioned teeth, a wedging element movable relative to said pawl element, said wedging element being in wedging engagement with pawl element, and means for yieldably urging said wedging element in a direction to lmaintain said pawl element in driving engagement with said driven element, said wedging element tending to maintain said pawl element in driving engagement with said driven element during movement of said pawl element in a direction opposite to said first mentioned direction, and said wedging element permitting said pawl element to withdraw from driving engagement with said driven element during movement of said pawl element in said iirst mentioned direction.

3. An intermittent rotary drive mechanism comprising the combination of a rotatable driven element, an oscillatable pawl element, one of said elements having a plurality of teeth therearound, the other of said elements having at least one tooth engageable with said first mentioned teeth, a wedging element movable relative to said pawl element, said wedging element being in wedging engagement with said pawl element and adapted to urge said pawl element into driving engagement with said driven element during movement of said pawl element in one direction, said wedging element permitting said pawl element to withdraw from driving engagement with said driven element during movement of said pawl element in the opposite direction, means for yieldably urging said wedging element in said opposite direction tending to maintain said pawl element in engagement with said driven element, and a second resilient means urging said pawl element into engagement with said driven element.

4. An intermittent rotary drive meohanism comprising the combination of a rotatable driven element, an oscililatable pawl element, one of said elements having a plurality of teeth therearound, the other of said elements having at least one tooth engageable with said first mentioned teeth; means forming a base, a wedging element intermediate said base and said pawl element, said wedging element being movable relative to said pawl element, and means for yieldably urging said wedging element in one direction into wedging engagement with said pawl element whereby to maintain said pawl element in driving engagement with said driven element during movement lof said pawl element in an opposite direction, said wedging element permitting said pawl element to withdraw from driving engagement with said driven element during movement of said pawl element in said one direction.

A An intermittent rotary drive mechanism comprising the combination of a rotatable driven element, an oscillatable pawl element, one of said elements having a plurality of teeth therearound, the other of said elements having at least one tooth engageable with said iirst mentioned teeth, each of said teeth oi' said elements having a driving side and a non-driving side, the non-driving sides of said teeth extending at an angle to the direction of movement of said elements, a wedging element engageable with said pawl element, said wedging element having a wedging surface extending at substantially the same. angle as said non-driving tooth sides, and means for yieldably urging said wedging element in -a direction tending to maintain said pawl element in engagement with said driven element, said wedging element being adapted to maintain said pawl element in driving engagement with said driven `element during movement of said pawl element in an opposite direction, and said wedging element permitting said pawl element to Withdraw from driving engagement with said driven element during 6 movement of said pawl element in said iirst mentioned direction.

6. An intermittent rotary drive meohanism comprising the combination of a rotatable driven element, an oscillatabl'e pawl element, one of said elements having a plurality of teeth therearound, the other of said elements having at least one tooth engageable with said iirst mentioned teeth, the sides of each of said teeth extending at an angle to the direction of movement of said one element, means forming a base, a wedging element intermediate said base and said pawl element, and spring means urging said wedging element in one direction to wedge said pawl element in driving engagement with said driven element during movement of said pawl element in an opposite direction, the wedging angle of said wedging element being approximately the same as said tooth side angle, said wedging element permitting said pawl element to withdraw from driving engagement with, said driven element during movement of said pawl element in said one direction.

7. An intermittent rotary drive mechanism comprising the combination of a rotatable driven element, Ian oscillatable pawl element, one of said elements having a plurality of V-shaped teeth therearound, the other of said elements having at least one tooth engageable with said first mentioned teeth, means forming a base, a wedging element intermeditae said base and said pawl element, said wedging element having two opposing wedging surfaces, said wedging surfaces extending at substantially the same angle to the direction of movement of said drive element as the sides of said teeth, and spring means for urging said wedging element in one direction whereby to maintain said pawl in driving engagement with said driven element during movement of said pawl element in a rst direction land for permitting said pawl element to withdraw from driving engagement with said driven element during movement of said pawl element in an opposite direction, said spring means being reversible to urge said wedging element in an opposite direction whereby to maintain said pawl element in driving engagement with said driven element during movement of said pawl element in said second direction and for permitting said pawl element to withdraw from driving engagement with said driven element during movement of said pawl element in said first direction.

8. An intermittent rotary drive mechanism comprising the combination of a driven element, a cammng element, a pawl intermediate said elements, means supporting said pawl and said elements for relative movement about a common axis, said last mentioned means permitting axial movement of said pawl, means yieldably urging said camming element in one direction about said axis, said pawl and said driven element having `a first set of inter-engaging V-shaped teeth, said pawl and said camming element having `a ,second set of inter-engaging V-shaped teeth, and spring means urging said pawl axially into engagement with said driven element, said pawi being axially movable out of driving engagement with `said driven element by said trst set of teeth during rocking movement of said pawl in said one direction, said second set of teeth being effective to `aid said spring means to maintain said pawl in driving engagement with said driven element during rocking of said pawl in the opposite direction.

9. An intermittent rotary drive mechanism comprising the combination of a driven element, a camming element, Ia pawl intermediate said elements, means supporting said pawl and said elements for relative movement about a common axis, said last mentioned mean-s permitting axial movement of said pawl, means yieldably urging :said camming element in one direction about said axis, said pawl land said driven element having a first set of inter-engaging projections, each of said Iiirst set of projections having a driving surface and a non-driving surface, the non-driving surfaces of said projections extending at an angle to the direction of movement of said pawl about said axis, said pawi and said camming element having a second set of inter-engaging projections, each of said second set of projections having inter-engaging surfaces extending at an angle to the direction of movement of said pawl about said axis, said pawl being axially movable away from said driven element by said non-driving sun-faces of said iirst set of projections during rocking of said pawl in said one direction, and means comprising said second set of projections for maintaining said pawl in driving engagement with said driven element during rocking of said pawl in the opposite direction.

10. An intermittent rotary drive mechanism comprising the combination of a shaft, a driven element on said shaft, a camming element on said shaft, a pawl on said shaft intermediate said elements, said pawl and said driven element having -a iirst set of inter-engaging teeth, said teeth having inter-engaging surfaces extending at an angle to the direction of movement of said pawl about said shaft, said pawl and said camming element having a second set of inter-engaging teeth of greater height than said rst set, said second set of teeth having interengaging surfaces extending `at an angle to the direction of movement of said pawl about said shaft, means urging said camming element in one direction about said shaft, said pawl being axially movable an amount greater than the height of said rst set of teeth and less tha-n the height of said second set of teeth whereby said first set is eiective to move said pawl out ot driving engagement with said driven element during rocking of said pawl in said one direction and said `second set of teeth is effective to hold said pawl' in driving engagement with Said driven element during rocking of said pawl in the opposite direction.

1l. An intermittent rotary drive mechanism comprising the combination `of a driven element, a camming element, a pawl intermediate said elements, means supporting said pawl and said elements for relative movement about a common axis, means for oscillating said pawl about said axis, said pawl and said driven element having a first set of inter-engaging V-shaped teeth, said pawl and said camming element having a second set of interengaging V-shaped teeth of greater height than said iirst set, said pawl being axially movable an amount greater than the height of said rst set and less than the height of said second set, and spring means for urging said camming element in `one direction about said axis whereby to maintain said pawl in driving engagement with said driven element during rocking of said pawl in a iirst direction and to permit said pawl to withdraw from driving engagement with said driven element during rocking of said pawl in a second and opposite direction, said spring means being reversible whereby to urge said camming element in an opposite direction to maintain said pawl in driving engagement with said driven element during rocking of said pawl in said second direction and for permitting said pawl to withdraw from driving engagement with said driven element during rocking of said pawl in said tirst direction.

12. An intermittent rotary drive mechanism comprising the combination ot a rotatable driven element having a plurality of teeth therearound, ya pawl engageable with said teeth, means supporting said pawl for oscillating movement about the axis of said driven element,

a base, a camming element intermediate said pawl and .said base, said camming element being movable about ,said axis, said camming element and said base having .inter-engaging surfaces extending substantially parallel to one side of a said tooth of said driving element which is engaged by said pawl, and spring means for urging 4said camming element in one direction about said axis into wedging engagement with said base and said pawl, said camming element being adapted :to maintain said pawl in driving engagement with said driven element yduring rocking o-f said pawl in an opposite direction, .and said camming element permitting said pawl to withdraw from driving engagement with said driven element yduring rocking `of said pawl in said one direction.

13. An intermittent rotary drive mechanism comprising the combination of a rotatable driven element, an Iosciilatable pawl element, one of said elements having a plurality of teeth therearound, the Iother of said elements having `at least one tooth engageable with said iirst mentioned teeth, means forming a base, a wedging element intermediate said pawl element and said base, means for yieidably urging said wedging element in one ldirection to wedge said pawl element in driving engagement with said driven element during movement of said pawl element in yan opposite direction whereby to advance said driven element from one position to another, said wedging element permitting said pawl element rto withdraw from driving engagement with said driven element during movement of said pawl element in said one direction, and means for detenting said driven element in each of said positions.

14. An intermittent rotary drive mechanism comprising the combination `of a rotatable driven element, an oscillatable pawl element, yone of said elements having a plurality of teeth therearound, the other of said elements having at least one tooth engageable with said first mentioned teeth, means Storming a base, a wedging element intermediate said base and said pawl element, spring means urging said wedging element in one direction into wedging engagement with said pawl element whereby to maintain said pawl element in driving engagernent with said driven element during movement of said pawl element in the opposite direction, said Wedging element permitting said pawl element to withdraw from driving engagement -with said driven element during movement of said pawl element in said one direction, and means for detenting said driven element during said withdrawal of said pawl from driving engagement with said driven element.

References Cited in the file of this patent UNITED STATES PATENTS 447,648 Sutherland Mar. 31, 1891 1,039,023 Calkins Sept. 17, 1912 1,281,486 Bertin Oct. 15, 1918 1,366,531 Garelli Jan. 25, 1921 2,266,283 Spengler Dec. 16, 1941 2,377,583 Smith June 5, 1945 2,923,165 Platzer Feb. 2, 19.60 2,954,701 Berill Oct. 4, 1960 3,036,474 Perez May 29, 1962 3,044,314 Kilingler July 17, 1962 

1. AN INTERMITTENT ROTARY DRIVE MECHANISM COMPRISING THE COMBINATION OF A ROTATABLE DRIVEN ELEMENT, AN OSCILLATABLE PAWL ELEMENT, ONE OF SAID ELEMENTS HAVING A PLURALITY OF TEETH THEREAROUND, THE OTHER OF SAID ELEMENTS HAVING AT LEAST ONE TOOTH ENGAGEABLE WITH SAID FIRST MENTIONED TEETH, A WEDGING ELEMENT MOVABLE RELATIVE TO SAID PAWL ELEMENT, SAID WEDGING ELEMENT BEING ENGAGEABLE WITH SAID PAWL ELEMENT AND ADAPTED TO MAINTAIN SAID PAWL ELEMENT IN DRIVING ENGAGEMENT WITH SAID DRIVEN ELE- 